48 lines
890 B
C
48 lines
890 B
C
/*
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key.c
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*/
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#include <stdint.h>
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#include "stm32l031xx.h" /* IRQ disable/enable */
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#include "key.h"
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#define KEY_QUEUE_MASK 0x0f
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#define KEY_QUEUE_MAX (KEY_QUEUE_MASK+1)
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uint8_t volatile key_queue[KEY_QUEUE_MAX];
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uint8_t volatile key_queue_start = 0;
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uint8_t volatile key_queue_end = 0;
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int key_add(uint8_t key)
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{
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uint8_t new_end;
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new_end = key_queue_end;
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new_end++;
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new_end &= KEY_QUEUE_MASK;
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if ( new_end == key_queue_start )
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return 0; /* buffer is full */
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key_queue[key_queue_end] = key;
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key_queue_end = new_end;
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return 1;
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}
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uint8_t key_get(void)
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{
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uint8_t key;
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uint8_t new_start;
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if ( key_queue_start == key_queue_end )
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{
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return KEY_NONE;
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}
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//__disable_irq();
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key = key_queue[key_queue_start];
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new_start = key_queue_start;
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new_start++;
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new_start &= KEY_QUEUE_MASK;
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key_queue_start = new_start;
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//__enable_irq();
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return key;
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}
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